Such fluid turbines are used to generate energy from water, air or other fluid flows. In the operation of such a rotor, at least one rotor blade moves in the direction of or together with the fluid flow and at least one rotor blade moves against the direction of the fluid flow or against the fluid flow. For example, a wind-driven turbine rotor is known from DE 10 2009 042 536 A1, consisting of a vertically rotating rotor with rotor blades coupled to it having a shape which conforms to the inside segment of the housing and the outer swing radius. The inner segment of the housing tapers towards the rotor.